Interpreting the effects of interfacial chemistry on the tribology of diamond-like carbon coatings against steel in distilled water

Friction was controlled by the formation of a transfer layer, reducing adhesive interactions between surfaces. Subsequently, a gradual increase in friction was observed, and suggested to relate to an increase in the shear strength of the transfer layer due to adsorption of oxidative species. This was modelled using the Elovich equation for gas adsorption kinetics.